I'm not sure if the editors are not aware of this but minicomi has a lot of manga in there that have no entries in MU. I don't know enough Japanese to contribute entries, but here is their site:

https://www.mincomi.jp/go/

The Minicomi (Minna no Comic) publisher page for MU is here (with only 2 entires as of the time of this writing):

https://www.mangaupdates.com/publishers.html?pubname=Minna+no+Comic